The instructable will show you how to make simple Wind Tunnel at your home / School. This project shall let students understand concept of Wind Tunnel, how they are used in testing aerodynamics of objects.

This project shall also help you understand suction, exhaust of fans / propellers, how toggle switches work.

Also this Wind Tunnel can be used as test bed to test aerodynamics of any object that can be placed inside Wind Tunnel.

Note : I had created this project with the help of my Infosys Colleagues (Rashmi and Daya). We had participated in Week of Making competition initiated by our company Infosys. We also got help from Maker space “Heramb MakerLab” for using tools.

Step 1: Bill of Material

Soft Drink Bottle: We recommend to use bottle of Fanta soft drink, as it has got required shape.
Box: Box can be used for placing soft drink bottle.
Fevicol / FeviStick / Glue: For joining two objects. These are available in local shop.
Wires: Wires to connect different electrical objects. Buy thin wires from electronics shop (not electrical hardware shop).
D.C. Motor with Propeller: You can buy small D.C. motor with propeller in any electronics shop. This motor specification should be 1.5 – 9 volts.
Small Wooden block: This is for holding motor in place. This can be found at home or carpenter shop.
Dhoop (Incense sticks) with stand: Most of the Indian families have Dhoop (Incense sticks) in their house.You can use Dhoop (Incense sticks) with its holder for creating smoke effect. Alternatively you can use anything which can generate smoke like wood chips, coal etc with proper safety (placed in metal container).
Wire Coil: To create stand for placing Dhoop (Incense sticks) holder.
Tooth Pick: Mostly available at home.
L.E.D strip: These are cheap L.E.D strip which can be bought from Electronics Shop. Use green color L.E.D.strip.
Hack saw: To cut bottle and any other hard object for fitment. You can get small hack saw blade with itsframe in local electrical hardware shop.
Toggle Switch: This is two way toggle switch providing ON/OFF logic. This can be bought in Electronics shop.
9 Volt Battery with connectors: You can find 9 Volt battery with connectors in Electrical hardware shop orElectronics Shop.
4 AA Battery Holder: This battery holder can be found in Electronics Shop.
4 AA Batteries: This battery can be found in any local shop.
Solder gun (optional): This is used to solder the wire with the toggle switch. This is an optional device and connecting the wires to the switch can also be done by hand.
Hot glue gun (optional): This gun is used to affirm all the wind tunnel connections permanently.
Decorative Material (optional): Thermocol, Color Chart paper, pencils, ruler, tape etc. can be used for decoration and labeling purposes.

Step 2: Cut Soft Drink Bottle

Cut the given soft drink bottle at two end so it would form perfect wind tunnel shape.

Step 3: Mount Bottle on Box

Place cut bottle on box and glue it temporarily using fevicol.

Step 4: DC Motor Mounting

Stick D.C motor with Propeller to wooden block.

Now place wodden block on box such a way that fan can rotate inside bottle (bottom portion of bottle shall form exhaust)

Step 5: Add Switch to Motor

Now create small holes in box behind the wooden block to take motor wires inside box.

Connect Toggle switch , battery connector and Motor wires together to form a circuit which shall make motor ON / OFF.

Make sure fan is rotating in such a way that it pulls air from neck of the bottle. This can be tested by placing small paper inside bottle when fan is rotating.